Meeting Abstract
The ability to carry loads in flight is critical for survival and reproduction in many flying insects. Although some insects carry loads near or directly below the center of mass, mud daubers, yellowjackets, mason bees, and many other insects carry food or nesting materials in the mandibles, which noticeably shifts the center of mass forward. Such fore-aft shifts in the center of mass are expected to have important consequences for flight control, but the kinematic changes required to maintain controlled flight and the resulting effects on maneuverability and stability have not yet been explored. To address these questions, we filmed blue orchard bees (Osmia lignaria) at 5000 fps as they transported mud loads in their mandibles during nest construction. We also filmed bees as they carried artificial loads mounted directly above the center of mass and on the ends of long booms, which shifted the center of mass even farther forward than mandible loading. Using reconstructed body and wing trajectories we tested the hypothesis that responses to imbalanced loads would be similar those exhibited during active pitching maneuvers in other insects. We also tested the hypothesis that imbalanced loads would reduce flight performance in turbulent flow in a wind tunnel to a greater degree than similar loads carried directly above the center of mass. If bees control body pitch using the same strategies they use to compensate for imbalanced loads, such loads may limit control authority and introduce unique challenges for these insects in inclement weather. Principles extracted from our observations of maneuvering flight while unevenly loaded may also inform design efforts for small aerial vehicles carrying off-center loads attached to arms, grabbers, or other manipulators.
